How to check the references in your essay

Reviewed by Benjamin Lohrer, editor at corrected.eu · Updated: 31 August 2026

Source references in an essay

If you want to build a reliable source reference in your essay or term paper, work systematically: first settle your checking question, then examine the licence and category of the original source, sort all mandatory details and finally check that your reference matches the evidence exactly.

Building the reference in your essay: licence and category

When you cite in your essay, do not start with an unordered collection of data. Start with a precise guiding question. Work out in advance: what information do you need to add to the work so that its legal category and the permitted scope of use are clearly recognisable? That way you end up with a sound reference and a short record of how you checked the references in your essay.

Every source you use can be assigned to a category by its licensing. Someone else's work is either in the public domain, protected by copyright or published under a special licence. Because each of these categories calls for its own mandatory details in the reference, a superficial glance at a passage of text or a graphic is not enough: always read the actual licence and usage notes directly at the original source.

In Germany, every work is in principle regarded as protected by copyright as long as no different status is noted. If you want to take over protected material, you generally need permission to use it. For educational institutions, however, a statutory relief applies for teaching purposes without a profit motive: up to 15 per cent or a maximum of 20 pages of a protected work may be quoted, and a complete source reference remains mandatory. Note, though, that this rule applies only to Germany and exactly this educational purpose. If you study elsewhere, check what applies in your country.

For your own paper, a general overview will not help; only a check of the individual case does. For every source you draw on, record in writing the category you established, your exact purpose of use and the reference data derived from them. If you want to train your academic writing deliberately, first define the concrete checking question and the aim of your investigation. Each finished reference then relates exactly to the material you have looked at and checked yourself.

Whenever you have to write an essay or term paper, note down for each piece of evidence exactly which work is in front of you, which statement you take from it and which licence-related additions the reference requires. Treat the other components of an academic paper just as systematically in larger projects. Never rush from the finding on one single passage to a blanket rule for other sources.

How to check the references in your essay: the components

Your source check divides into seven successive working steps. Keep a short working note on each stage, so that you can trace at any time how your initial checking question became a fully secured reference.

• Set the checking question: state in writing which aspect of the source you want to clarify. A targeted question on the licence category of the work, on required additional details or on the legal limits of use makes sense. As when formulating a research question, you gain clarity by concentrating on a single decision per checking step.
• Evaluate the original source: check directly in the work or in the associated licence notes which protection status is named there. Record whether public domain, copyright protection or a special licence is stated explicitly. If a decisive feature is missing, note the open point for further research instead of merely guessing the status.
• Record the rules of use: compare the source with your concrete purpose of use. If the use is for teaching purposes at an educational institution without a profit motive, also check the permitted limit of up to 15 per cent or a maximum of 20 pages of a work. At the same time, document that the duty to give a correct source reference remains fully in force within this limit.
• Sort the evidence: bring together only the data that are relevant to your checking question. Separate cleanly between bibliographic details of the work, the statements of the licence and your concrete way of using the work in the text. When you then create your bibliography, you transfer this secured data into the required order.
• Write out the reference: put the reference together only from the material you checked and ordered beforehand. This does not replace a coherent academic argument in the running text, but the source reference makes it unmistakably visible which concrete evidence you base your statement on.
• Compare the result: check the finished reference once more word for word against the original source and your notes. When you give source references correctly, this means in concrete terms that every detail you take over on title, author and licence must be documented in the original.
• State the limits of what you can say: record explicitly which questions your check does not answer. The licence information you evaluated clarifies the source category, the scope of use and the necessary additional details, but it says nothing about the specific examination regulations of your university or the legal position outside Germany.

How your finished reference is formally designed depends on which of the common citation styles your department prescribes. So always consult your institute's current guide instead of assuming, unchecked, the German citation style with footnotes or Harvard referencing in the running text. What matters is that you can build your reference so that all the licence and work data you have checked are fully reflected and the origin of each piece of information stays traceable.

The checking process in detail: from the work to the finished reference

Keep in mind where this fits in your overall plan: if you compare different methods of academic work, nothing methodological can be derived from the legal and formal check of a single source. Nor does the distinction between qualitative and quantitative research decide which licence details belong in your reference. So always clarify separately whether your working step requires empirical research data or concerns the formal documentation of a source you used.

1. Note the guiding question: record your concrete checking question in one sentence, for example: which mandatory details does this work require because of its licence category? The result is a precisely limited working question.
2. Secure the source: document the exact title of the work, the exact place where you found it and all visible licence and usage notes in your records. The result is a source that can be identified beyond doubt.
3. Read off the category: use the original details to examine whether public domain, regular copyright protection or a special licence applies. The result is a documented categorisation including where it was found.
4. Determine the purpose of use: settle conclusively whether the use takes place within an educational institution for teaching purposes without a profit motive. Only if this condition really applies to your paper do you apply the statutory limit of up to 15 per cent or a maximum of 20 pages. The result is a documented purpose of use.
5. Select the details: filter out exactly the information required for the licence category you established and for the complete source reference. The result is a cleaned list of data without speculative additions.
6. Formulate the reference: transfer your checked data into the required citation format. If the format requirement is unclear, look at the official guidelines of your degree programme instead of guessing house rules at your university. The result is a complete draft of your reference.
7. Compare: check every single element of your draft once more against the original source and the usage rules you noted. The result is an overview of confirmed evidence data and any points still to be clarified.
8. Add the limits: finally record that your assessment applies only to the source examined, its category and the purpose of use you checked in your paper. The result is robust documentation of your check.

Worked example: checking an online figure in your essay

Take a concrete example from student life: a student wants to include in her essay a figure published on the internet. The question she formulated beforehand is: which licence and provenance details must she check at the image source and add to the reference?

In the first step she secures the exact online location and the licence note shown there. Because the web page contains no indication that the work is in the public domain, she does not assume that status unchecked. Instead she reads the linked licence text and the terms of use in detail.

Then she classifies her purpose of use: in her essay at an educational institution, the figure serves teaching purposes only, without a profit motive. She therefore checks the framework that applies to quotations in an educational context and records explicitly that a complete source reference remains mandatory even where use is permitted.

In the last step she cleanly separates the secured evidence from unsupported assumptions. The checked material includes the exact title of the figure, the place where it was found and the licence information stated explicitly; she builds her reference from exactly these components. Whether the same graphic could also be used outside non-commercial educational purposes she does not assess, but marks as a limit of her check.

This case does not provide a rigid pattern for any image file, but it shows precisely how you check a source systematically, select the relevant mandatory details and document the limits of your statement. If you are drafting the outline of your essay at the same time, link this checking note directly to the chapter in which the figure will later appear.

Final check: keep the content check and the formal check apart

Before you submit, check your references in two clearly separate passes: first the assignment in terms of content and law, and only then the outward formatting. That way a reference that is neatly formatted does not pass as checked in content by mistake.

Delimitation in terms of content

• Is your checking question precisely worded and aimed at a concrete result for the source in question?
• Was the original source clearly named and evaluated for licence category and protection status?
• Have you recorded the conditions that apply to your specific purpose of use in your studies?
• Are documented original details strictly separated from mere assumptions or unchecked additions?
• Can you trace without gaps how the original source, the selected mandatory details and the finished reference are connected?
• Does your conclusion relate only to the work checked and the documented purpose of use?
• Are all the limits of your check documented, especially regarding jurisdiction, purpose of use, extent of the quotation and missing licence data?

Formal check

• Compare the exact spelling of all work titles, authors' names and designations character by character with the original source.
• Check whether all mandatory components of the required citation form are included in the reference.
• Place the short reference or footnote exactly at the point in your essay where you actually use the other work.
• Check each individual reference in the text first on its own, separately from the alphabetical sorting when you create the bibliography.
• Keep strictly to the citation styles prescribed by your chair instead of assuming unchecked formatting rules to be binding.
• Finally make sure that by clearly marking every borrowed thought you can avoid plagiarism.

If a checking question stays unanswered, you may derive neither a tacit permission nor a blanket ban from it. Record instead, precisely, which information is still missing at the source. In this way your documentation rests only on secured facts, because a purely formal correction of spelling never replaces the check of the original source in terms of content.

Sources and status

• Categories of sources (licences), Serlo: de.serlo.org (checked on 2026-08-31)

Frequently asked questions about source references in an essay